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A pixel by any other name...



 
 
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  #1  
Old April 12th 13, 12:18 AM posted to rec.photo.digital
Jennifer Murphy[_2_]
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Posts: 127
Default A pixel by any other name...

I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).



Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)



Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.




  #2  
Old April 12th 13, 12:28 AM posted to rec.photo.digital
philo [_4_]
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Posts: 70
Default A pixel by any other name...

On 04/11/2013 06:18 PM, Jennifer Murphy wrote:
I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:


snip

You may want to read this article:



http://www.kenrockwell.com/tech/raw.htm


  #3  
Old April 12th 13, 12:44 AM posted to rec.photo.digital
nospam
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Posts: 24,165
Default A pixel by any other name...

In article , philo*
wrote:

You may want to read this article:


http://www.kenrockwell.com/tech/raw.htm


actually, you *don't* want to read that article.

that person makes stuff up and intentionally misleads people, thinking
it's some sort of game (he admits this on his about page).
  #4  
Old April 12th 13, 12:56 AM posted to rec.photo.digital
nospam
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Posts: 24,165
Default A pixel by any other name...

In article , Jennifer
Murphy wrote:

I think digital photography is beyond my mental capacities (sigh).


i think you're trying to make it more complicated than it needs to be.

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be?


i don't know where you're getting the raw files but they're not
straight from the cameras. the numbers are wrong.

also keep in mind that a jpeg can be resized to anything you want.

if you are going to compare raw versus jpeg, they must be unmodified
out of the camera, with the settings set to maximum resolution.

I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.


it should be the same, unless the jpeg has been resized, cropped or
otherwise modified.

Here are a couple of examples:


Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).


i don't know where you got that raw file but it's not from a canon 5d.
a canon 5d (mark i) has 4368 x 2912 pixels, for 12.7 megapixels, not 4
megapixels. the aspect ratio on a 5d is 3:2, so the jpeg was cropped.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)


something is wrong there too. the dmc-g1 has 12 megapixels, not 2.76 mp.

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.


psd is photoshop, not raw, and a nikon d700 has 12 megapixels, not 7.

is that the one your friend adjusted the perspective? if so, that
explains why it's 7 mp and why it's a photoshop file. it was resized
and cropped in photoshop to fix the perspective distortion.
  #5  
Old April 12th 13, 01:14 AM posted to rec.photo.digital
Savageduck[_3_]
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Posts: 16,487
Default A pixel by any other name...

On 2013-04-11 16:18:33 -0700, Jennifer Murphy said:

I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).


In the above case you have two different dimension sizes; the CR2 is
2496 x 1664 p giving you 4.15MP and the jpeg is 3156 x 2678 p at 8.9MP,
an almost 50% difference due to the dimensional difference. These are
MPixels which deal only with physical dimensions.
Note the actual file (disk size) sizes are 12.92 MB for the CR2 and
7.07 MB for the JPEG. There is still more data contained in the RAW CR2.
I suspect you have an adjusted and size extrapolated JPEG there, not a
JPEG immediately converted from the CR2. The 16-bit CR2 is unadjusted
and not altered in any way.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)


This is a similar scenario to the Canon example. the dimensional size
of the jpeg has been enlarged, while the true size of the files, the
RW2 and the compressed jpeg reflect the truth of the data contained in
each.
Also in this case the 16-bit RW2 is unadjusted

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.


This is a different situation. First PSD is not the native RAW format,
for that it should be an NEF. PSD is an Adobe file type, as sub-type of
TIFF which preserves layer and adjustments made with Photoshop and some
other editing software.
Note that the dimensions of both the PSD and the JPEG are identical,
and so both have the same total pixels, 7.09MP.

The disk or file size tells the other side of the story. The
adjustments and edits were probably made to the converted RAW NEF file
and then saved to the hard drive. It will not be saved as a NEF, but as
a 16-bit, uncompressed PSD, retaining all the data of the adjustments.
Then to save it as a compressed JPEG it will be saved as an 8-bit
compressed JPEG


--
Regards,

Savageduck

  #6  
Old April 12th 13, 01:35 AM posted to rec.photo.digital
nospam
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Posts: 24,165
Default A pixel by any other name...

In article 2013041117141337709-savageduck1@REMOVESPAMmecom,
Savageduck wrote:

The 16-bit CR2 is unadjusted
and not altered in any way.

....
Also in this case the 16-bit RW2 is unadjusted


one would expect that to be the case for raw, but the pixel dimensions
don't match the number of pixels the cameras actually have. something
else is going on.
  #7  
Old April 12th 13, 01:39 AM posted to rec.photo.digital
nospam
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Posts: 24,165
Default A pixel by any other name...

In article , nospam
wrote:

if you are going to compare raw versus jpeg, they must be unmodified
out of the camera, with the settings set to maximum resolution.


actually, that should really be native resolution, not maximum.

some cameras have a fake 'high res' mode that is interpolated up from
its native resolution.
  #8  
Old April 12th 13, 04:26 AM posted to rec.photo.digital
Jennifer Murphy[_2_]
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Posts: 127
Default A pixel by any other name...

On Thu, 11 Apr 2013 19:56:08 -0400, nospam
wrote:

In article , Jennifer
Murphy wrote:

I think digital photography is beyond my mental capacities (sigh).


i think you're trying to make it more complicated than it needs to be.


It wouldn't be the first time...

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be?


i don't know where you're getting the raw files but they're not
straight from the cameras. the numbers are wrong.


I have a couple of friends with cameras that are better than mine. I
asked them for the "raw" files and that's what I got.

also keep in mind that a jpeg can be resized to anything you want.


And once resized, the number of pixels as reported by IrfanView could be
anything, right?

if you are going to compare raw versus jpeg, they must be unmodified
out of the camera, with the settings set to maximum resolution.


I'm starting to think that my friends may not know as much about how
their cameras work as I thought they did.

I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.


it should be the same, unless the jpeg has been resized, cropped or
otherwise modified.

Here are a couple of examples:


Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).


i don't know where you got that raw file but it's not from a canon 5d.
a canon 5d (mark i) has 4368 x 2912 pixels, for 12.7 megapixels, not 4
megapixels. the aspect ratio on a 5d is 3:2, so the jpeg was cropped.


I was told by the owner that it was the raw camera file. (sigh)

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)


something is wrong there too. the dmc-g1 has 12 megapixels, not 2.76 mp.


Again, I asked for the raw camera file and that's what I was given.

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.


psd is photoshop, not raw, and a nikon d700 has 12 megapixels, not 7.


This is very disappointing. I am reluctant to go back to my friends and
suggest that they con't know what the heck they are doing.

is that the one your friend adjusted the perspective? if so, that
explains why it's 7 mp and why it's a photoshop file. it was resized
and cropped in photoshop to fix the perspective distortion.


There is one that she cropped in PS, but the one that is 130MB (.psd)
was supposed to be a raw camera file.

Maybe I need to hire a professional photographer to do it right. I've
spent sop much time trying to get a good shoot, what I could have paid
for it several times over.

Thanks for the patient instruction.
  #9  
Old April 12th 13, 04:28 AM posted to rec.photo.digital
Jennifer Murphy[_2_]
external usenet poster
 
Posts: 127
Default A pixel by any other name...

On Thu, 11 Apr 2013 17:14:13 -0700, Savageduck
wrote:

On 2013-04-11 16:18:33 -0700, Jennifer Murphy said:

I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).


In the above case you have two different dimension sizes; the CR2 is
2496 x 1664 p giving you 4.15MP and the jpeg is 3156 x 2678 p at 8.9MP,
an almost 50% difference due to the dimensional difference. These are
MPixels which deal only with physical dimensions.
Note the actual file (disk size) sizes are 12.92 MB for the CR2 and
7.07 MB for the JPEG. There is still more data contained in the RAW CR2.
I suspect you have an adjusted and size extrapolated JPEG there, not a
JPEG immediately converted from the CR2. The 16-bit CR2 is unadjusted
and not altered in any way.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)


This is a similar scenario to the Canon example. the dimensional size
of the jpeg has been enlarged, while the true size of the files, the
RW2 and the compressed jpeg reflect the truth of the data contained in
each.
Also in this case the 16-bit RW2 is unadjusted

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.


This is a different situation. First PSD is not the native RAW format,
for that it should be an NEF. PSD is an Adobe file type, as sub-type of
TIFF which preserves layer and adjustments made with Photoshop and some
other editing software.
Note that the dimensions of both the PSD and the JPEG are identical,
and so both have the same total pixels, 7.09MP.

The disk or file size tells the other side of the story. The
adjustments and edits were probably made to the converted RAW NEF file
and then saved to the hard drive. It will not be saved as a NEF, but as
a 16-bit, uncompressed PSD, retaining all the data of the adjustments.
Then to save it as a compressed JPEG it will be saved as an 8-bit
compressed JPEG


You make similar points to nospam. Thanks.
  #10  
Old April 12th 13, 04:55 AM posted to rec.photo.digital
Savageduck[_3_]
external usenet poster
 
Posts: 16,487
Default A pixel by any other name...

On 2013-04-11 20:28:05 -0700, Jennifer Murphy said:

On Thu, 11 Apr 2013 17:14:13 -0700, Savageduck
wrote:

On 2013-04-11 16:18:33 -0700, Jennifer Murphy said:

I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).


In the above case you have two different dimension sizes; the CR2 is
2496 x 1664 p giving you 4.15MP and the jpeg is 3156 x 2678 p at 8.9MP,
an almost 50% difference due to the dimensional difference. These are
MPixels which deal only with physical dimensions.
Note the actual file (disk size) sizes are 12.92 MB for the CR2 and
7.07 MB for the JPEG. There is still more data contained in the RAW CR2.
I suspect you have an adjusted and size extrapolated JPEG there, not a
JPEG immediately converted from the CR2. The 16-bit CR2 is unadjusted
and not altered in any way.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)


This is a similar scenario to the Canon example. the dimensional size
of the jpeg has been enlarged, while the true size of the files, the
RW2 and the compressed jpeg reflect the truth of the data contained in
each.
Also in this case the 16-bit RW2 is unadjusted

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.


This is a different situation. First PSD is not the native RAW format,
for that it should be an NEF. PSD is an Adobe file type, as sub-type of
TIFF which preserves layer and adjustments made with Photoshop and some
other editing software.
Note that the dimensions of both the PSD and the JPEG are identical,
and so both have the same total pixels, 7.09MP.

The disk or file size tells the other side of the story. The
adjustments and edits were probably made to the converted RAW NEF file
and then saved to the hard drive. It will not be saved as a NEF, but as
a 16-bit, uncompressed PSD, retaining all the data of the adjustments.
Then to save it as a compressed JPEG it will be saved as an 8-bit
compressed JPEG


You make similar points to nospam. Thanks.


To keep things simple, here is the data for a CR2 and corresponding
matched jpeg, shot in a Canon G11 capturing RAW+JPEG (Fine Large).

Filetype: CR2
Pixels: 2736x3648 or 9.98 MP for a 10MP camera.
File/disk size: 14.2MB

Filetype: JPEG (ex-camera, fine, large)
Pixels: 2736x3648 or 9.98 MP for a 10MP camera.
File/disk size: 4.2MB

Out of the camera the dimensional size and megapixels for both the RAW
CR2 and the JPEG will always be the same provided you select the
largest possible in-camera JPEG setting.

The initial file/disk size is going to be dependent on the the content
of the image, with the addition that the JPEG's size will depend on the
in-camera compression, in this case an approximately 7:1 compression
ratio.

--
Regards,

Savageduck

 




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